A power supply controller includes a semiconductor switch to be connected between a power source and a load. The power supply controller turns on/off the semiconductor switch so as to control power supply to the load. Such a power supply controller has a function to protect a load circuit etc. without using any fuse element (see Patent Document 1). Specifically: the power supply controller determines whether overcurrent of equal to or greater than a predate mined value passes through the semiconductor switch; and, upon determination that overcurrent has passed, the power supply controller turns on/off the semiconductor switch. Thereafter, upon occurrence of predetermined cycles of the on-off state, the power supply controller determines that the circuit is short-circuited, and the power supply controller maintains the semiconductor switch in the off state.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2000-315588